The overall goal of this proposal is to test whether AIDS-associated B-cell non-Hodgkin's lymphomas (NHL) represent outgrowths of viral or self antigen activated B-cells, to define the spectrum of immunoglobulin variable (V) region genes utilized by these lymphomas and to test whether subsets of lymphoma would utilize identical V regions. If viral antigens are found to drive the pre-malignant B-cell proliferation or common V region determinants are shared between different lymphomas, non-immunosuppressive therapeutic approaches to the prevention and treatment of AIDS-lymphomas could be devised. In a preliminary analysis of two AIDS lymphoma cell lines we found one AIDS NHL IgM to be HIV-1 reactive (2F7) and the other to be self reactive (10C9). Rather than laboriously and inefficiently establish other AIDS NHL cell lines, we will create AIDS NHL hybridomas for testing of IgM antigenic specificity. In order to rapidly clone V regions and compare V region sequences between large numbers of patient specimens, a recent advance in polymerase chain reaction (PCR) technology will allow the rapid and direct cloning of rearranged V regions from tumor genomic DNA to test whether, as in other classes of lymphoid malignancy, subsets of AIDS NHL will be found to utilize common V regions. Specific aims: 1) To test IgM's from monoclonal and polyclonal AIDS-associated lymphomas for reactivity with a panel of viral (HIV-1, EBV, CMV) and self antigens, and utilizing polymerase chain reaction (PCR), to clone the IgM variable region genes from at least ten monoclonal tumors in order to define the spectrum of V region genes (and V region modifications) used by these lymphomas. 2) To characterize the molecular nature of the monoclonal idiotype shared between the 10C9 self reactive lymphoma cell line and 5 of 21 monoclonal AIDS-associated lymphomas. 3) To use specific AIDS lymphoma V region (CDR2) oligonucleotides from the ten cloned VH regions including the 10C9 V region for analysis of PCR amplified VH genes from frozen and formalin fixed archival AIDS NHL specimens (currently greater than 125 at SFGH) to determine the prevalence of specific VH region utilization in AIDS-associated lymphomas.